Due to the amazing power of computer systems, computer systems become essential data processing apparatuses in the digitalized and electronic societies. Input devices such as mouse devices have been widely employed in a computer system for cursor control. Via the mouse device, the user may communicate with the computer system. Nowadays, with increasing demand of using the mouse device, the mouse devices having a variety of functions and hardware configurations are designed and the associated technologies are well established in order to meet the users' requirements.
Conventionally, the mechanical mouse device or the optical mouse device has a left click button and a right click button. By clicking the left click button and the right click button, corresponding micro switches under these click buttons are triggered to issue corresponding control commands. As known, when the left click button or the right click button is clicked, a loud noise is generated from the corresponding micro switch. In a case that many people in a conference room are using mouse devices, the noisy sounds emitted from the micro switches may bother the attendants.
The detailed structure will be illustrated as follows with reference to FIG. 1A and FIG. 1B. FIG. 1A is a schematic side view of a conventional micro switch. FIG. 1B is a schematic cutaway view of the conventional micro switch. The micro switch 100 principally includes a base 101, a pressing element 109 and a top cover 102. A perforation 103 is formed in the top cover 102. The micro switch 100 further includes a common terminal 105, a normally open terminal 106, a normally close terminal 104 and a resilient piece 107. The common terminal 105 is disposed on an edge of the base 101. The normally open terminal 106 is disposed on another edge of the base 101. The normally close terminal 104 is disposed beside the normally open terminal 106. The resilient piece 107 has a first end arranged on the common terminal 105 and a salient 108 is formed on a second end of the resilient piece 107. In a case that the no external force is exerted on the resilient piece 107, the salient 108 at the second end of the resilient piece 107 is contacted with the normally close terminal 104. Moreover, the pressing element 109 includes a button portion 110 and a protrusion edge 111. The button portion 110 of the pressing element 109 penetrates through the perforation 103 of the top cover 102, and the protrusion edge 111 adjacent to the button portion 110 is in contact with the periphery of the perforation 103 of the top cover 102 to prevent the pressing element 109 from gliding out of the perforation 103.
The micro switch 100 is actuated to generate a switching signal by rendering mutual touch between the resilient piece 107, the common terminal 105, the normally open terminal 106 and the normally close terminal 104. In a case that the no external force is exerted on the resilient piece 107, the salient 108 at the second end of the resilient piece 107 is contacted with the normally close terminal 104. Whereas, if the pressing element 109 is pressed down to have the salient 108 of the resilient piece 107 separate from the normally close terminal 104 and have the resilient piece 107 come to contact with the normally open terminal 106, a loop is defined by the common terminal 105, the resilient piece 107 and the normally open terminal 106. Meanwhile, a conducting signal is asserted from the micro switch 100. When the external force is eliminated, the resilient piece 107 returns to its original position and the salient 108 at the second end thereof will come to contact with the normally close terminal 104 again.
As previously described, if the pressing element 109 is pressed down to have the resilient piece 107 come to contact with the normally open terminal 106, a loop is defined and a conducting signal is generated. When the external force is eliminated, the restoring force of the resilient piece 107 may push back the pressing element 109 to its original position. During the resilient piece 107 returns to the original position, the salient 108 on the resilient piece 107 may collide with the normally close terminal 104. Since the salient 108 and the normally close terminal 104 are collided with each other during operation of the micro switch 100, loud noise is readily generated.
Therefore, there is a need of providing a micro switch with reduced noise to obviate the drawbacks encountered from the prior art.